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WESTSIDE WATER ASSN

PWS ID: WA5394950 · Vashion Island, Washington 98070

WESTSIDE WATER ASSN serves 562 people in Vashion Island, Washington using Groundwater water sources. It has 65 recorded EPA violations, including 0 health-based violations. No PFAS contamination was detected in UCMR5 testing.

Water Quality Snapshot: WESTSIDE WATER ASSN

WESTSIDE WATER ASSN is a private-owned community water system that delivers drinking water to 562 residents in Vashion Island, Washington (King County) through 239 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 65 total violations for this system , of which 0 (0%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 62 monitoring and reporting violations are on file. The most recent violation on record dates to 2020.

The most frequently cited contaminant at this system is Nitrate, recorded in 11 violations (MR). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.

Across Washington, EPA tracks 4,557 public water systems serving 9,736,844 people, with 314,648 cumulative violations and 20,590 health-based violations on record. About 92% of systems in the state carry at least one violation, and state-wide the average per system is 69 violations. WESTSIDE WATER ASSN's 65 violations sit below the Washington average. Statewide, 98 of 247 UCMR5-tested systems have reported PFAS detections (39.7%). All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

Population Served
562
Total Violations
65
Health-Based Violations
0
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Private
Connections
239
County
King
School/Daycare
No
MCL Violations
0
Monitoring Violations
62
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Nitrate MR 11 2020
Lead and Copper Rule MR 10 2007
Diquat MR 6 2008
TTHM MR 4 2020
Total Haloacetic Acids (HAA5) MR 4 2020
Coliform (TCR) MR 4 1992
ETHYLENE DIBROMIDE MR 2 2008
Aldicarb MR 2 2008
1,2-DIBROMO-3-CHLOROPROPANE MR 2 2008
Aldicarb sulfone MR 2 2008
OXAMYL MR 2 2008
Carbofuran MR 2 2008
Aldicarb sulfoxide MR 2 2008
Consumer Confidence Rule Other 1 2015
Revised Total Coliform Rule MON 1 2018
Selenium MR 1 1979
Chromium MR 1 1979
Fluoride MR 1 1979
Gross Alpha, Excl. Radon and U MR 1 1979
Mercury MR 1 1979
Arsenic MR 1 1979
Barium MR 1 1979
Cadmium MR 1 1979

Verify This Water System

The figures above are aggregated from EPA's public databases. To verify the underlying records — or to file a complaint, request a Consumer Confidence Report, or check current monitoring status — go directly to the federal and state regulators that enforce the Safe Drinking Water Act for WESTSIDE WATER ASSN.

Federal Source of Truth

EPA SDWIS — Federal Reports

EPA's Safe Drinking Water Information System (SDWIS) holds the federal compliance record for every regulated public water system. Open the system-level report by PWS ID:

View PWS ID WA5394950 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Washington Drinking Water Authority

Washington State Department of Health — Office of Drinking Water is the primacy agency that licenses and inspects WESTSIDE WATER ASSN under EPA-delegated authority.

Open WA regulator portal

Source: Washington State Department of Health — Office of Drinking Water

Violation Timeline

Each row links to the EPA SDWIS public record for verification. Cross-reference the contaminant code on EPA's federal report to see violation dates, return-to-compliance status, and enforcement actions.

Year (latest) Contaminant Category Count EPA Record
2020 Nitrate MR 11 SDWIS / WA5394950 / 1040
2020 TTHM MR 4 SDWIS / WA5394950 / 2950
2020 Total Haloacetic Acids (HAA5) MR 4 SDWIS / WA5394950 / 2456
2018 Revised Total Coliform Rule MON 1 SDWIS / WA5394950 / 8000
2015 Consumer Confidence Rule Other 1 SDWIS / WA5394950 / 7000
2008 Diquat MR 6 SDWIS / WA5394950 / 2032
2008 ETHYLENE DIBROMIDE MR 2 SDWIS / WA5394950 / 2946
2008 Aldicarb MR 2 SDWIS / WA5394950 / 2047
2008 1,2-DIBROMO-3-CHLOROPROPANE MR 2 SDWIS / WA5394950 / 2931
2008 Aldicarb sulfone MR 2 SDWIS / WA5394950 / 2044
2008 OXAMYL MR 2 SDWIS / WA5394950 / 2036
2008 Carbofuran MR 2 SDWIS / WA5394950 / 2046
2008 Aldicarb sulfoxide MR 2 SDWIS / WA5394950 / 2043
2007 Lead and Copper Rule MR 10 SDWIS / WA5394950 / 5000
1992 Coliform (TCR) MR 4 SDWIS / WA5394950 / 3100

How WESTSIDE WATER ASSN Compares

Cross-reference this system's record against state averages and the federal MCL framework for context.

Metric WESTSIDE WATER ASSN Washington avg Federal benchmark
Total violations 65 69 SDWA compliance — any non-zero count is a recorded breach
Health-based violations 0 4.5 Indicates a contaminant exceeded a federal MCL
PFAS detection None 39.7% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 562 2,137 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 4,557 regulated public water systems in Washington.

Federal MCL reference — Safe Drinking Water Act thresholds ▼
Contaminant Federal MCL / Action Level Note
Lead 0 mg/L (Action Level: 0.015 mg/L) Lead and Copper Rule treatment technique
Arsenic 0.010 mg/L (10 ppb) Health-based MCL since 2006
Total Coliform Treatment technique (RTCR) Indicator organism, monitoring trigger
PFOA / PFOS (PFAS) 4.0 ppt each (final 2024 rule) Compliance deadline 2029
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is WESTSIDE WATER ASSN water safe to drink? ▼
WESTSIDE WATER ASSN (PWS ID: WA5394950) has 65 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 562 people using Groundwater sources.
How many people does WESTSIDE WATER ASSN serve? ▼
WESTSIDE WATER ASSN serves 562 people in Vashion Island, Washington. It is a Private-owned system using Groundwater water sources with 239 service connections.
What type of violations does WESTSIDE WATER ASSN have? ▼
WESTSIDE WATER ASSN has 65 total violations: 0 health-based violations (MCL exceedances or treatment failures), 62 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in WESTSIDE WATER ASSN water? ▼
No PFAS testing data is available for WESTSIDE WATER ASSN under the EPA's UCMR5 monitoring program.
What water source does WESTSIDE WATER ASSN use? ▼
WESTSIDE WATER ASSN uses Groundwater as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.
Where does this data come from? ▼
All data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS tracks compliance for all public water systems regulated under the Safe Drinking Water Act.

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Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. This data is provided for informational purposes only.

Read our methodology — how this data is sourced, computed, and verified.

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